Model duplicating device



April 14, 1936. J. R. SCHWARTZ MODEL DUPLICATING DEVICE Filed NOV. 21, 1955 INVENTOR JACOB B. sea/444572 M ATTORN EY Patented Apr. 14, 1936 UNITED STATES PATENT OFFICE MODEL DUPLICATING DEVICE Jacob R. Schwartz, Brooklyn, N. Y. Application November 21, 1933, Serial No. 698,982 2 Claims. (01. 18-33) My present invention relates to form duplicating devices, and more particularly concerns an improved type 'of dental model duplicating flask.

One of the main objects of the present inven- 5 tion is to provide a device for duplicating configurations of objects, the device essentially comprising a receptacle to receive the object to be duplicated, means for anchoring the object to the receptacle, and a receptacle closure means filled with an elastic plastic impressionable material and adapted to surround the object with such material when in operative closure position, the impression material being solidified at room temperature.

Another important object is to provide a model duplication device, or flask, which consists of a base member provided with a model receiving recess, a readily breakable material being used to anchor the model to the recess, a closure member provided with a recess adapted to receive an impression material, and means for rigidly securing said closure member to said base member.

Another object of the invention is to provide a novel method of, and means for, producing duplicate dental casts which consists in anchoring the original cast to a receptacle, surrounding the cast with a softened elastic impression material which is normally'solid at room tem- 30 perature, permitting the impression material to solidify, making a cast of the impression in the impression material, softening the solidified material and. surrounding the original cast with the softened material to make a new impression.

Still another object of the invention may be said to provide a. dental duplicating flask which is capable of producing as many duplicate casts of an origin-a1 dental cast as is desired without the need for disturbing the position of the ,orignal cast in the flask, and without replacing the impression material from its receptacle, the flask further including a readily breakable anchoring material for maintaining the original cast in undisturbed position in the flask until the anchoring material is broken up.

Still other objects of my present invention are to improve generally the simplicity and efiiciency of model duplication devices, and especially to provide a duplication flask for reproducing object shapeswhich is not only reliable and durable in operation, but is economically manufactured.

The novel features which I believe to be char- 'acteristic of my invention are set forth in particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, will best be understood by reference to the following description, taken in connection with the drawing, in which I have indicated diagrammatically several constructions whereby my invention may be carried into efl'ect.

In the drawing:-

Fig. 1 is a perspective view of the flask in operative condition, y 7

Fig. 2 is a, perspective view of the flask in open position,

Fig. 3 is a sectional view alongline 3-3 of Fig. 1 in the direction of the arrows,

Fig. 4 is a fragmentary view showing a modified form of securing clamp.

Referring now to the accompanying drawing, wherein like reference characters in the different views designate similar construction elements, Figs. 1 and 2 show the appearance of the duplicating device in two different conditions. The device, or flask, generally comprises a base portion I and a closure portion 2, both cooperating to provide areceptacle for a model, or object, 4 whose configuration is to be duplicated. The base I specifically has a D shape, this being also true of the closure member 2, but any other shape could Well be employed. There are four essential elements provided on the base I.

These four elements include the foundation, or body, element '5; the trough 6; the pusher element 1; and the securing clamps 8, 9. The body 5 may be composed of bronze, aluminum, steel or any material which is suitable for the purposes of this invention. The body 5 is provided with a pair of spaced, opposed recesses, both of substantially the same configuration, and one of said recesses being the trough- 6. The opposite recess is designated by the numeral 6', and functions as a housing for' the pusher screw.

The trough 6 is provided by the'wall In which has a D shape and is integral with the body 5. The wall I0 is set in from the outer edge of the body 5, the numeral 5' designating a supporting face for the closure member. It will be noted that the trough 6 has its inner vertical face outwardly flared. This is shown in Fig. 3 by the numeral II. The trough 6 functions as a receptacle for the model 4, the base of the latter being disposed on the base II of the trough 6. It additionally acts as a receptacle for material I2 to be employed for rigidly anchoring the model 4 to the base II and wall I0. v

The pusher element comprises a steel disc, or circular plate, l3 affixed to the pusher screw [4 by a machine screw [5. The exposed end of the screw |4--is provided with a manually operable element 1'. The disc I3 is disposed in a recess l3 provided in the base ll of trough 6. The recess I3 is disposed at substantially the center of the base H, and is dimensioned to snugly receive the disc I3. The threaded surface of screw I4 is disposed in a threaded bore I4 provided in the body 5, the bore connecting the recess l3 with the recess 6. Normally, that is with the disc in the position shown in Fig. 3, a part of the pusher screw 1 will extend into recess 6. The function of the pusher screw is to break the bond between the anchoring material [2 and the object 4, this being accomplished by turning the handle I in a direction to move the disc |3 out of recess l3.

The fourth essential element of the base member comprises the means for securing the closure 2 to the base member. Clamps 8 and 9 perform this function, the clamps being pivotally secured to opposite sides of the body 5. The clamp 8 includes an L shaped arm having the lower end of its vertical portion 8 pivotably secured to face l6 by a conventional hinge arrangement H. The horizontal extension l8 of the clamp 8 is provided with a wing nut l9 which cooperates with the vertical threaded bolt of disc 20. This type of clamp securing means is very well known to those skilled in the art, and can be replaced by any other desired type of securing means.

The clamp 9 is of the same construction, and for this reason the numerals l1, l8, l9 and 20 are used to designate the duplicates of the elements of clamp 8. The numeral 9 designates the vertical portion of clamp 9. Both clamps 8 and 9 may be composed of steel, and it is within the scope of the present invention to employ more than two clamps to secure the closure member 2 to the base member Both elements 8' and 9 fit into special recesses in the closure and base. members, the numerals 2| and 2| designating the recesses provided on the opposite sides of body 5 to receive the vertical portions 8' and 9 respectively. It will be observed that the depth of these recesses is only a frac tion of the thickness of the vertical clamp por tions, this being clearly depicted in Fig. 3.

The remaining member of the duplication flask is the closure member 2, and this latter member may be composed of the same material as that of the base member Essentially the top, or closure, member 2 is a hollow shell which has a configuration similar to that of the base member I. The outer faces of the side walls of the closure member, when in operative position as in Fig. 1, are co-planar with the same faces of the base member, and the height of the side walls of the closure member will depend on the use to which the device is to be put. The general dimensional proportions between the closurev member, the object 4 and the base memher l are shown in Fig. 3.

The closure member is provided with a pair of vertical recesses 22 and 22', the recess 22 being in alignment with the recess 2| and the recess 22' being aligned with recess 2| when the device is in the operative position of Figs. 1 and 3. In other words, the recesses 22 and 22 are extensions of recesses 2| and 2| respectively, and function to receive the upper sections of the vertical clamp portions 8' and 9.

The inner face of the closure side walls has its lower portion designed to provide a snug fit with the base member This is accomplished by having the bottom edge of the side walls of the .same dimensions as the edge 5'. The inner face of the side walls is, further, provided with a sharp extension 23 adapted to engage the upper face of trough wall ID, the extension 23 having a rearwardly sloping face substantially in the same plane as the sloping face ll of the trough 6. The inner face of the wall section between overhanging extensions 23 and edge 5' is in contact with the outer face of wall l0.

The discs 20 and 20 bear upon the top wall 24 of the closure member 2 adjacent the recesses 22 and 22'. A plurality of aligned apertures, or holes, 25 are provided in the side walls of the closure member 2 adjacent the top wall 24. These openings function as vent, or escape, holes for the excess duplication material which may be extruded from the closure member upon securing of the clamps 8 and 9. It is to be clearly understood that the number and location of such escape holes are dependent upon the particular circumstances encountered in actual usage of the device. For example, the top wall 24 may be provided with such escape openings in addition to, or exclusive of, the side walls. Again, more than one of such openings may be provided in the closure side walls.

In Fig. 4 is shown a modification of the clamp securing means. Only one of the clamps is here utilized, as for example the clamp 8. The disc 28 is replaced by a disc 30 of greater diameter disposed substantially at the center of the top wall 24. The horizontal section I8 of clamp 8 is made longer, but otherwise the construction of the clamp 8 is the same as in Figs. 1, 2 and 3. In this form, of course, the recesses 2| and 22' are unnecessary, and are therefore not employed, only the recesses 2| and 22 being retained.

The manner of using the duplicating device, or flask, will now be explained, particular reference being made to Fig. 3. Assuming that it is desired to make a duplicate of the object 4, in this specific case a dental cast, the latter is placed on the base ll of the base member The disc I3 is, of course, adjusted to the position shown in Fig. 3. The anchoring material |2 has been previously poured into the trough 6; and here the anchoring material isv plaster of Paris. It is to be understood that cement, artificial stone or similar materials can be used in place of plaster of Paris. The model 4 is disposed in the plaster While the latter is still soft, and it is to be clearly understood that experience will show how much is needed when the model is disposed in the trough 6. The surface of thematerial I2 is then smoothed down to a height such that it is coplanar with the upper edge surface of wall Ill.

The closure member 2 is now filled with the impression material (not shown to preserve simplicity of disclosure) to be used; This material is preferably a plastic, elastic impression compo sition which is normally in a solid state at room temperature, but is softened, so that it is impressionable, when subjected to the temperature of moist or dry heat. Such a material may be any plastic rubber composition well known to those skilled in the dental art. The'specific composition of the material employed is immaterial, since many different types of materials may be utilized, as long as it becomes impressionable when heated and becomes solid at room temperatures. Of course, other materials may be employed, such as normally gelatinous materials, but they are not as desirable in this form of flask as the aforementioned type of materials.

However, an adapter can readily be employed for gelatinous materials. Such an adapter has in general the construction of the closure member 2, except that the top wall 24 is removable.

The closure member containing the plastic impression material is now placed over the base member as shown in Fig. 2, and brought downward until in the position shown in Fig. 1. The wing nuts l9, I9 are brought into the position shown in Fig. 3, the clamps 8 and 9 having first been positioned in the positioning recesses. The model 4 will not be disturbed during the procedure since the plaster of Paris l2 has set and firmly anchors the model in position. The impression of the configuration of model 4 is made in the impression material, and when the latter solidifies the impression is fixed in it. The clamps 8 and 9 may now be removed, and the closure member 2 is separated from the base member l by simply pulling apart of the members; the closure member being then employed to receive the plaster of Paris, or other casting material, to be used in making the cast of the impression.

The pusher element 1 is now actuated by turning handle I. The disc I3 is elevated, thus breaking the plaster bond between the plaster l2 and the surface of model 4. In this way the model 4 can be easily, and without danger of damage to it, removed from the trough 6. Of course, if desired, the member 2 containing the impression material may be reheated to render plastic the material, and a new impression taken of the object 4. In that case the material I2 is not broken up by the pusher element as described above.

In this way any number of duplicate casts of model 4 may be made. The original cast 4 may be of any composition such as plaster of Paris, artificial stone, metal bone, precious stones, wood or other materials used for castings. By making duplicate plaster casts of the impression taken of the original 4, it is possible to greatly extend the life of the original model. In dental work this is of great value because the original cast is desired to be kept undamaged as long as possible.

The value of using an elastic impression material which is normally solid at room temperature will now be seen. Even when solidified, removing the closure member from the base member I does not affect the impression. The material is sumciently elastic to yield, and can be withdrawn from between the inclined teeth of model 4 without changing the impression. Particularly in the case of dental casts showing excessive undercuts it will be found that the solidified impression material can be readily withdrawn from the cast 4 without in any way affecting the character of the undercuts in the impression.

While I have indicated and described several constructions for carrying my invention into effect, it will be apparent to one skilled in the art that my invention is by no means limited to the particular constructions shown and described, but that many modifications may be made without departing from the scope of my invention, as set forth in the appended claims.

What I claim is:-

1. A model duplication flask comprising a receptacle provided with a relatively deep trough for receiving said model, a'model in the trough, a material in said trough for anchoring said model to the trough base and substantially filling the portion of the trough left free by the model, and a closure member forsaid receptacle adapted to confine an impression material around said model in said trough.

2. A model duplication flask comprising a receptacle provided with a relatively deep trough for receiving said model, a model in the trough, a material in said trough for anchoring said model to the trough base and substantially filling the portion of the trough left free by the model, a closure member for said receptacle adapted to confine an impression material around the model in said trough, and means in the trough base for breaking the bond between the anchoring material and said model.

JACOB R. SCHWARTZ. 

